Take a look at the ApraxiaKids website. There is a difference between a child experiencing developmental delay in speech and language, and a child with normal communication skills (speech rhythms, understanding, etc) who cannot or is impared creating the speech to communicate. Both have good opportunity for success, but the latter requires specialized, more intensive therapy to achieve maximum potential.
With so little use of language at this age, you should definitely arrange a Speech/Language evaluation. This would help pin down what might be contributing to the delay.